Refrigeration compressor for vehicles

ABSTRACT

A refrigeration compressor for vehicles provided with a discharging port formed at a cap portion thereof for discharging compressed refrigerant and with a suction port formed in a crank shaft room for leading the refrigerant thereinto. The cap portion is provided with several component passages for discharging refrigerant having different size spaces and different directions so that the cap functions as a muffler.

United States Patent 1191 Nakayama 1 1 Jan. 30, 1973 [54] REFRIGERATION COMPRESSOR FOR [56] References Cited VEHICLES UNITED STATES PATENTS lnveflwrl w Nakflyama, Kariya, Japan 2,020,096 11 1935 Bergstrom ..417 312 Assigneez Kabushiki Kaisha y Jidoshok 2,235,962 3/1941 Hornady ..47l/3l2 kl Selsakusho A Japan Primary Examiner-William L1 Freeh [22] Filed: April 28; 1971 Assistant ExaminerLeonard Smith PP No'z 138,185 Attorney-Mdton J. Wayne v [57] ABSTRACT [30] r s" Applicafio Priority Data A refrigeration compressor for vehicles provided with a discharging port formed at a cap portion thereof for Aprll 29, 1970 Japan ..45/36607 discharging compmssed refrigerant and with a suction port formed in a crank shaft room for leading the [52] US. Cl....'.... ..4l7/3l2 refrigerant thereinto; The cap portion is provided with [5 l] Int. Cl ..F04b 39/12 everal component passages for discharging [58] Field of Search ...-..4l7/312, 364, 4l5 902 refrigerant having different size spaces and different CONDENSER directions so that the cap functions as a muffler.

5 Claims, 8 Drawing Figures SHEEI 2 OF 5 PATENTEDJAN 30 I975 CONDENSER ENGINE PATENTEDJAM30 1975 3,713,758 v sumanrs PATENTEDJAN a0 1915 SHEET l} [1F 5 PATENTEDJAN 30 I973 sum 50F s Fig. 7

REFRIGERATION COMPRESSOR FOR VEHICLES BRIEF SUMMARY OF THE INVENTION The present invention relates to a refrigeration compressor for vehicles, such as a reciprocating type compressor, and more particularly relates to a refrigeration compressor provided with a discharging port formed at a head portion thereof for discharging compressed refrigerant such as freon gas and with a suction port formed in a crank shaft chamber for leading the refrigerant thereinto.

In the conventional refrigeration gas compressor provided with suction and discharging valves at the head portion thereof, as these valves are disposed at the above-mentioned portion adjacently, if a modified arrangement of an inlet or outlet pipe line is required, several pipe connections are necessary to avoid mutual interference between outlet and inletpipe lines. Consequently, an excess space must be provided and further, possible leakage of gas from these pipe lines must be prevented.

In the conventional reciprocation type refrigeration compressor, the refrigerant is sucked into a compression chamber from a cylinder'head and discharged from the chamber through the same cylinder head. It is difficult to supply a sufficient quantity of refrigerant when a piston moves inward to the crank-shaft chamber so as to supply the refrigerant into the compression chamber. The main reason for the above-mentioned drawback is due to the resistance caused by the piping for connecting the evaporator to the compressor.

Consequently, lowering of the working efficiency of the compressor is inevitable.-

The principal object of the present invention is to provide a refrigeration gas compressor of simple construction utilized for vehicles in which the noise created by discharging refrigerant is considerably decreased.

Another object of the present invention is to provide a refrigeration gas compressor capable of being mounted on various vehicles of different types even though the gas compressor is a single model, so that the direction of the discharging aperture can be easily altered.

A further object of the present invention is to provide a refrigeration gas compressor having strong durability and superior working efficiency of compression.

These and other objects of the present invention will become more apparent from the following description reference being made to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a perspective view of a refrigeration compressor according to the present invention,

FIG. 2 is a side view, partly in section, of the refrigeration compressor shown in FIG. 1,

FIG. 3 is a sectional view, taken along a line lIIIlI, in FIG. 2,

FIG. 4 is a sectional view of the refrigeration compressor, taken-along a line IV-IV in FIG. 2,

FIG. 5 is a longitudinal section view of a piston, taken along a line V-V, in FIG. 4,

FIG. 6 is a back side view of a rear side cover of the refrigeration compressor shown in FIG. 1,

FIG. 7 is a sectional side view of the cover, taken along a line VII-VII IN FIG. 6,

FIG. 8 is a sectional front view of a part of the refrigeration compressor, taken along a line VIIIVIII, in FIG. 2.

DETAILED DESCRIPTION Referring to the drawings which show a preferred embodiment of the present invention, a housing 1 comprises a crank shaft chamber la provided with a sump for carrying a quantity of lubricating oil, a cylindrical compression chamber lb formed above the crank shaft chamber 1a and a seal chamber 1e formed in front of the crank shaft chamber la. The apertures of the housing 1, which are formed at a top, bottom, front and rear side thereof, are closed by a cap 2, a bottom plate 3, a front side cover 4, a read side cover 5, and a seal member 21. The seal chamber 1e defines the inside walls of the housing 1 and the front side cover 4, and a bearing support member lg for supporting the bearing 6. The lower portion of the bearing support member lg is cut-off so as to provide a circular edge which is coaxial to the bearing 6, whereby a space If is formed between the circular bottom edge and the bottom plate 3. The space If connects the seal chamber 1e to the crank shaftchamber 1a as shown in FIG. 2. As shown in FIG. 3, the cap 2 is provided with four apertures for permitting the insertion of respective bolts 19 in such a way that these apertures are symmetrically arranged along a circle which is coaxial to the circular top edge of the housing 1. Therefore, it is possible to mount the cap 2 on the housing 1 in four different ways with angular difference. The inside diameter of the cap 2 is larger than the diameter of the peripheral cylindrical surface of a portion of the housing 1 which forms the compression chamber 1b so that when the cap 2 is mounted upon the housing 1, an annular space 1d is formed between the inside wall of the cap 2 and the peripheral cylindrical surface of the above-mentioned portion of the housing 1. A discharging aperture 2a is formed at a lower portion of the cap 2 and consequently, the discharging aperture 2a is connected to the compression chamber 1b through the annular space Id. In other words, the annular space Id is a portion of a passage for discharging the refrigerant. A further portion of the discharge passage is formed by spaces between peripherally spaced wall portions 2b projecting downward in opposition to an upper edge of upwardly projecting walls of housing 1 as shown in FIGS. 2 and 3. The crank shaft chamber 1a is provided with a suction inlet 1h at a suitable position of its upper portion so as to supply the refrigerant into the compression chamber 1b as shown in FIG. 1. A front end portion of the crank shaft 8 extends from the front side cover 4 and engages with a driving mechanism of an'engine (not shown). The rotation of the crank shaft 8 is converted to a reciprocal linear motion by way of a connecting rod 11 and a piston pin 12 and this reciprocal linear motion is transmitted to the piston 10 in said compression chamber 1b.

The piston 10 is provided with a hollow cylindrical space beside a portion for connecting with the piston pin 12, and is provided with a plurality of apertures 10a at the head portion thereof in such a way that these apertures are adjacently arranged on*the circular edge of the head 'portion. A suction valve 13 is mounted upon the head of the piston by means of a bolt 14 so that the above-mentioned apertures 10a are closed when the gas pressure in the compression chamber lb is higher than that in the. crank shaft chamber la, and are opened in the reverse condition. As shown in FIG. 4, the suction valve 13 is a circular thin steel plate provided with a pair of crescent cut-off portions 13a, 13b which are formed symmetrically with respect to the center of the circular suction valve 13. A valve plate 15 is disposed between the projections 2b of the cap 2 and top edge portion of the housing 1. Certain modifications of the above-mentioned projection 2b may be incorporated in the present invention. That is, a downward projecting cylindrical wall provided with a gas passage passing therethrough may be used instead of the above-mentioned projections 2b. Moreover, it is contemplated to utilize certain projecting members having a function for permitting free passage of refrigerant from the compression chamber lb into the annular space 1d after contacting the top inside wall of the cap 2. The valve plate 15 is provided with a discharging aperture 15a. A discharging valve 16 and a control plate 17 are mounted on the valve plate 15 by a bolt 18. The discharging valve 16 only opens the aperture 15a when the gas pressure in the space between the cap 2 and the valve plate 15 is lower than that in the compression chamber lb. The control plate 17 restricts the opening motion of the discharging valve 16. The discharging valve 16 is a thin steel plate. Referring to FIGS. 2, 6, and 7, the rear side cover 5 comprises a base portion 5a provided with a plurality of apertures 5b for inserting a respective fastening bolt and a pair of annular projections 5c and 5d coaxially projecting from the base portion 5a. Therefore, annular recesses 5f are formed therebetween. The outer annular projection 50 engages with housing 1 and the inner annular projection 5d engages with a bearing 7 which supports the crank shaft 8. The annular recesses Sfare divided into a plurality of small recesses by a plurality of ribs 5g. An annular sump Se is formed inside the space defined by the inner annular projection 5d and the base portion 5a. The outer annular projection 5c is provided with a cut-off groove 5h for returning splashed oil, while the inner annular projection 5d is provided with a funnel like aperture 5i at a position facing the groove 5h so that the annular recess 5fis connected to the annular sump 5e.

The above-mentioned apertures 5b for permitting the insertion of the respective bolts are arranged along a circle with an equal intervened space therebetween. The above-mentioned circle is coaxial to the rear side bearing 7. If, the crank shaft 8 is driven in a condition shown in FIG. 2, a lubrication oil in the sump of the crank shaft chamber la is splashed upward by the motion of the crank shaft 8 and a pair of balance weights 8b, and a portion of the splashed oil enters into the groove Sit and then is led into the sump 5e and a recess 8a formed at end portion of the crank shaft 8 by way of the annular recess 5f and the funnel-like aperture 5i. The'recess apertures 5b makes it possible to mount the cover 5 in four different ways, that is, the position of the above-mentioned groove 5h and the funnel-like aperture 51' in connection with the housing I can be suitably chosen with a 90 angular difference. In other words, even though the housing 1 is required to be mounted on a vehicle in a vertical or lying down condition, it is possible to position the groove 5h and the funnel-like aperture (51') above the sump 5e. The returning lubrication oil permeates into a space between the crank shaft 8 and the bearing 7 and is dropped to the sump of the crank shaft chamber la after lubricating the bearing surface.

When the above-mentioned refrigeration compressor is mounted on a vehicle, the discharging aperture 7 2a is connected to a condenser 26 by a connection pipe 27, while the suction inlet 1h is connected to an evaporator 22 by another connection pipe 23, and the crank shaft 8 is driven by an engine 24 through a connection 25 so as to drive the piston 10. According to the following steps (A), (B), (C) and (D), the refrigerant is sucked from the evaporator and then is compressed in the compression chamber 1b and discharged to the condenser. A. Lower dead point of the piston 10 (shown in FIG. 2)

In this point, the discharging valve 16 is urged downward by the gas pressure in the condenser side and closes the discharging aperture 150. The suction valve 13 closes the apertures 10a by its own resiliency while the gas pressures in the crank shaft chamber la and the compression chamber lb are maintained in a balanced condition. B. Upward stroke of the piston 10 In this condition, the refrigerant in the compression chamber lb is compressed and when the gas pressure in this compression chamber lb exceeds the gas pressure in the condenser side, the outlet valve 16 is urged to open and the refrigerant flows through the intervened spaces between the projections 2b of the cap 2 and the annular space 1d so that the refrigerant is lead to the condenser from the discharging aperture 2a. During this stroke, the suction valve 13 is urged downward by the gas pressure in the compression chamber lb so that the apertures 1011 are closed. Consequently, the leakage of the compressed refrigerant into the crankshaft chamber la by way of the apertures 10a can be prevented. Further, as the gas pressure in the crankshaft chamber la is lowered according to increase in the space of the crank shaft chamber la due to the upward movement of the piston 10, the refrigerant is positively led into the crank shaft chamber la from the evaporator. C. Upper dead point of the piston 10 When the compression stroke is completed, the gas pressure in thecompression chamber lb and that in the cap 2 are balanced so that the outlet valve 16 closes the discharging aperture by its own recovering force. The suction'valve 13 still closes apertures 10a by the gas pressure in the compression chamber lb in the same condition as that of the above-mentioned step (B).

D. Downward stroke of the piston 10 In this stroke, as the piston 10 moves downward while closing the discharging aperture 150 by the outlet valve 16, the gas pressure in the compression chamber 1b is lowered rapidly, and when the above-mentioned pressure is lowered below the gas pressure in the crankshaft chamber la, the suction valve 13 is urged upward to be opened by the gas pressure in the crank shaft chamber la so that the refrigerant in the crank shaft chamber la flows into the compression chamber lb by way of apertures 100 as shown in FIG. 5.

In the above-mentioned compressor, the refrigerant is previously led into the crank-shaft chamber la during the upward stroke of the piston 10. In other words, the refrigerant is previously led into the crank shaft chamber la before the downward stroke of the piston 10, and the refrigerant is led into the compression chamber 1b during the downward stroke of the piston 10. Consequently, sufficient quantity of refrigerant can always be supplied into the compression chamber lb without disturbance by the resistance caused by the piping arrangement. In other words, the compression efficiency can be enhanced remarkably.

According to the present invention, as very fine particles of the lubrication oil, which are created in the crank shaft chamber la by the rotation of the crank shaft 8 and the motion of the balance weight 8b, are carried into the compression chamber lb by means of the refrigerant flow, therefore, the inside wall, wherein the piston 10 slides, is lubricated. By the above-mentioned function, the wear of the sliding portion of the piston 10 can be reduced so that the durability of the compressor can be remarkably prolonged.

In the refrigeration compressor according to the present invention, as the discharging aperture and the suction inlet are separately arranged on the cap 2 and the crank shaft chamber 10, respectively, a gasket seal, which is an essential element of a reciprocating type compressor for preventing leakage of the refrigerant into a passage of suction gas from an adjacent passage of discharging gas, can be omitted.

Further, as the passage for discharging refrigerant comprises several component passages having different size spaces and different directions between the outlet valve 16 and the discharging aperture 2a, the noise created by discharging refrigerant can be remarkably lessened.

As the compressed refrigerant flows from the large space between the upper wall of the cap 2 and the valve plate through the narrow intervening spaces between the projections 2b and again expands in the annular space 1d, then reaches the discharging aperture 2a, the cap 2 functions as a muffler for decreasing noise.

As the discharging aperture 2a is arranged in the cap 2 and the position of the discharging aperture 2a can be chosen in any of the sides of the compressor by changing the setting engagement of the cap 2 upon the housing 1, the outlet pipe line arrangement of the compressor according to the present invention can be carried out very easily. The above-mentioned advantage enlarges the utilization of the compressor according to the present invention for various types of vehicles.

As shown in the above-mentioned embodiment, the rear side cover 5 is provided with a particular construction for lubrication, and when the temperature of the bearing surface of the bearing 7 is low, the viscosity of the lubrication oil on the bearing surface is high so that the quantity of the lubrication oil which drops into the sump of the crank shaft chamber 1a is large. In other words, a large quantity of lubrication oil is carried into the sump 5e. However, when the temperature of the bearing surface elevates, the viscosity of the lubrication oil is lowered so that the oil becomes easy to flow, and

consequently, a large quantity of lubrication oil flows into a space between the crank shaft 8 and the bearing surface of the bearing 7 and then drops to the sump of the crank shaft chamber la. By the above-mentioned function, the cooling effect by the lubrication oil to the bearing surface is enhanced. Further, in the compressor of the present invention, it is not required to apply a pump for lubrication. Consequently, an equivalent lubrication effect can be attained in either direction of the crank shafts rotation. This is also an advantage which permits utilization of the present compressor for various types of vehicles. Particularly, the present compressor can be safely applicable for Diesel engine vehicles which have possibility of reversible rotation at starting time.

As already illustrated in the above-mentioned embodiment, the seal chamber 1e is connected to the crank shaft chamber 1a, and when the crank shaft 8 is driven, the lubrication oil in the sump of the crank shaft chamber 1a is stirred so that the lubrication oil in the seal chamber 1e is also stirred as shown in FIG. 8. Consequently, the bearing 6 and the seal member 21 are sprayed by the lubrication oil,'thereby both members 6, 21 being suitably lubricated so that the durability thereof can be remarkably prolonged.

What is claimed is:

l. A refrigeration compressor connecting to a refrigerant evaporator and a refrigerant condenser comprising, a crank shaft driven by an engine, a reciprocal piston mounted on said crank shaft, a housing forming a chamber divided into a crank shaft chamber and a compression chamber by said reciprocal piston, a connecting passage for connecting said two chambers, a suction passage connecting said crank shaft chamber with said refrigerant evaporator, a discharging passage connecting said compression chamber with said refrigerant condenser, a first valve means disposed in said suction connecting passage for admitting one-way flowing of refrigerant from said crank shaft chamber to said compression chamber, a second valve means disposed in said discharging passage for admitting one-way flowing of refrigerant from said compression chamber to said discharging passage, a cap closely covering a top aperture of said housing, said cap forming several component passages for discharging refrigerant having different size spaces and different directions whereby said cap functions as a muffler, one of said cap component passages being formed by ,an annular space between an inside wall thereof and an outside wall of said housing, said annular space being utilized as a portion of said discharging passage.

2. A refrigeration compressor according to claim 1, wherein said cap is provided with at least one intervening wall formed at a head inside wall thereof, said intervening wall being provided with a gas passage, said intervening wall of said cap projecting downward from said inside wall thereof, and a bottom edge of saidintervening wall rigidly positioning a valve plate supporting said second valve means by positively urging said valve plate against an upper edge of said housing.

3. A refrigeration compressor according to claim 1, wherein said cap is provided with a discharging aperture formed at a side thereof, said cap is capable of being selectively fixed to said housing in connection with a position of said discharging aperture.

4. A refrigeration compressor according to claim 1 wherein said cap is provided with at least one intervening wall formed at a head inside wall thereof, said intervening wall is provided with a gas passage.

5. A refrigerant compressor according to claim 4, 

1. A refrigeration compressor connecting to a refrigerant evaporator and a refrigerant condenser comprising, a crank shaft driven by an engine, a reciprocal piston mounted on said crank shaft, a housing forming a chamber divided into a crank shaft chamber and a compression chamber by said reciprocal piston, a connecting passage for connecting said two chambers, a suction passage connecting said crank shaft chamber with said refrigerant evaporator, a discharging passage connecting said compression chamber with said refrigerant condenser, a first valve means disposed in said suction connecting passage for admitting one-way flowing of refrigerant from said crank shaft chamber to said compression chamber, a second valvE means disposed in said discharging passage for admitting one-way flowing of refrigerant from said compression chamber to said discharging passage, a cap closely covering a top aperture of said housing, said cap forming several component passages for discharging refrigerant having different size spaces and different directions whereby said cap functions as a muffler, one of said cap component passages being formed by an annular space between an inside wall thereof and an outside wall of said housing, said annular space being utilized as a portion of said discharging passage.
 1. A refrigeration compressor connecting to a refrigerant evaporator and a refrigerant condenser comprising, a crank shaft driven by an engine, a reciprocal piston mounted on said crank shaft, a housing forming a chamber divided into a crank shaft chamber and a compression chamber by said reciprocal piston, a connecting passage for connecting said two chambers, a suction passage connecting said crank shaft chamber with said refrigerant evaporator, a discharging passage connecting said compression chamber with said refrigerant condenser, a first valve means disposed in said suction connecting passage for admitting one-way flowing of refrigerant from said crank shaft chamber to said compression chamber, a second valvE means disposed in said discharging passage for admitting one-way flowing of refrigerant from said compression chamber to said discharging passage, a cap closely covering a top aperture of said housing, said cap forming several component passages for discharging refrigerant having different size spaces and different directions whereby said cap functions as a muffler, one of said cap component passages being formed by an annular space between an inside wall thereof and an outside wall of said housing, said annular space being utilized as a portion of said discharging passage.
 2. A refrigeration compressor according to claim 1, wherein said cap is provided with at least one intervening wall formed at a head inside wall thereof, said intervening wall being provided with a gas passage, said intervening wall of said cap projecting downward from said inside wall thereof, and a bottom edge of said intervening wall rigidly positioning a valve plate supporting said second valve means by positively urging said valve plate against an upper edge of said housing.
 3. A refrigeration compressor according to claim 1, wherein said cap is provided with a discharging aperture formed at a side thereof, said cap is capable of being selectively fixed to said housing in connection with a position of said discharging aperture.
 4. A refrigeration compressor according to claim 1 wherein said cap is provided with at least one intervening wall formed at a head inside wall thereof, said intervening wall is provided with a gas passage. 